This invention relates to pressure sensors. In particular this invention relates to robust, extremely compact differential pressure sensors.
Pressure transmitters are commonly used in industrial processes to measure and monitor pressures of various industrial process fluids such as vapors and gasses of engines and other power sources. Differential pressure transmitters generally include a pair of process fluid inputs which are coupled to a differential pressure sensor in the transmitter that responds to a difference in pressure between the two inputs. Differential pressure transmitters typically include a differential pressure sensor coupled to a pair of isolator diaphragms. The isolator diaphragms are positioned at the process fluid inlets and isolate the differential pressure sensor from process fluids being sensed. Pressure is transferred from the process fluid to the differential pressure sensor through a thermally stable fill fluid in a passageway extending from the isolator diaphragms to the differential pressure sensor.
There is a need for a compact differential pressure sensor in a small package with a MEMS sensing element that is stable over a range of operating temperatures.